Preservative compositions for the preservation of produce, i.e. fruit and vegetables, are known in the art. Preservation treatments can be applied on whole fruits and vegetables, e.g. as a post-harvest treatment, but also to preserve the quality of peeled, sliced or cut fruits or vegetables. The latter gain in importance as the demand for convenience food increases. For example, freshly cut apple slices turn brown and soggy within hours. By treating fruit or vegetables with a preservative composition, their so-called shelf life can be extended considerably.
An important aspect of preservative compositions is the taste they impart on the products they are applied upon. Ideally, preservative compositions do not alter the taste. In practice, a preservative composition may be a compromise between preservation and taste altering properties. A related aspect is that as a food product, the ingredients of a preservative composition fall under strict regulations. This means that not every compound or composition that shows good preservation properties is suitable for use as a preservative composition.
In respect of the above, WO9907230 discloses a method for preserving fresh fruit, in which a preservative solution is employed comprising ascorbate ions and calcium ions in an ion ratio of from 1.5:1 to 2.5:1. About the taste of preservatives or preservative compositions, WO9907230 mentions that fruit that is treated with citric acid, has a sour taste, becomes soft and soggy and usually turns brown within hours. Therefore, it is stated that a preservative composition should preferably lack citric acid. Further, a preservative composition A comprising 2 grams ascorbic acid, 4 grams calcium chloride, 2 grams citric acid, and 4 grams sodium acid pyrophosphate in 188 ml distilled water was used as a comparative preservative solution in the preservation of red delicious apple slices. This means that the molar ratio of ascorbate ions to calcium ions in preservative composition A is 0.31:1. The taste after treatment was assessed as very strong and considered unacceptable.